1. Field of the Invention
The present invention relates to a data recording method, an apparatus, and a program suitable for recording multimedia files.
2. Description of the Related Art
With recent diversification of moving image and audio encoding formats, there is a growing need for the capability of interchangeably processing such various formats in a unified framework. In response to this need, the International Organization for Standardization/International Engineering Consortium (ISO/IEC) JTC1/SC29/WG11 has standardized a general-purpose file format called the “ISO Base Media File Format” for recording moving-image and audio content data, such as MPEG data, into files.
Since the file format based on this standard is defined as a fundamental file format rather than a particular encoding format, a separate standard needs to be defined by partially extending this standard in order to support a particular encoding format or adjust to a particular objective. One typical example of such extensions is the “MP4 file format”, which is a standard file format for recording moving-image and audio encoded data in accordance with MPEG-4. Another example of format associated with moving images and audio in accordance with MPEG-4 is the 3GPP file format, which is defined by the Third Generation Partnership Project (3GPP) as a moving-image-file standard with restrictions on the assumption that it is used on wireless terminals, particularly on third-generation mobile phones.
Considering that a growing number of devices, such as digital cameras and cellphones, are employing these file formats to record moving-image and audio data encoded in accordance with MPEG-4, these file formats are likely to become more popular in the future.
Since MPEG-4 is a relatively high-compression encoding scheme with a superior error correction technique, especially in streaming distribution, such file format may also have applications to monitoring cameras (monitoring video) for storage of recorded data. With this being the situation, needs for storing long-hour monitoring video and audio on a recording medium have not been fulfilled because recording can be terminated at the time the capacity of the recording medium runs out, which is likely to occur if the recording medium does not have a sufficient capacity.
Needs for keeping (recording) at least the latest data may be fulfilled by recording data into divided files so that an old data file can be replaced with the latest data file when the recording medium does not have a sufficient capacity. In this approach for keeping (recording) the latest data on the recording medium, because data is saved in separate files, the files may be associated with one another by using a playlist to achieve operability. This approach, however, can be problematic in general with versatility and operability because the playlist function may not be available if the separate files are moved to another playback system for playback.
In this manner, the conventional techniques may have problems with, for example, general versatility and operability of recorded data when relatively long hours of moving image or audio data, such as monitoring video, is to be recorded on a recording medium with a limited capacity.